1. Field of the Invention
This invention relates to an opening/closing control device for controlling the opening and closing of a sliding door of a vehicle.
2. Description of the Related Art
Sliding door opening/closing control devices having a sliding door for sliding to open and close an opening in a vehicle body and a motor for driving this sliding door in opening and closing directions are disclosed in for example Japanese Utility Model Laid-Open Publications Nos. HEI 6-13915 and HEI 4-62883, Japanese Utility Model Post-Exam Publication No. HEI 6-13357 and Japanese Patent Laid-Open Publication No. HEI 4-285282.
Also, hinged vehicle door opening/closing control devices are disclosed in, for example, Japanese Patent Laid-Open Publications Nos. SHO 61-191781 and HEI 6-144000.
These known opening/closing control devices generally have a central processing unit (CPU) for controlling the operation of a motor for driving a door in opening and closing directions, a battery for supplying power to this CPU, a ROM containing a control program and a RAM for storing data.
The CPU executes program control of the motor by carrying out at a high speed the high-level computation necessary for controlling complicated opening and closing movements of the door.
The power consumed by the CPU is supplied from a battery mounted in the vehicle, and when the CPU is constantly in a state of performing high-level computation at a high speed the power consumption of the CPU is large and the electrical energy of the battery is consumed rapidly.
To deal with this problem, the battery is recharged with electricity generated using the rotation of the wheels while the vehicle is traveling. However, it is not possible to recharge the battery when the vehicle is stopped or parked and the wheels are not rotating. Consequently, it has been necessary to mount a large-capacity battery in the vehicle to provide for opening/closing control of the door when the vehicle is stopped or parked.
Also, because sliding door opening/closing control devices have not carried out opening/closing control of the sliding door when there has been no user-operation input for opening or closing the sliding door, when the vehicle has been stopped or parked on sloping ground such as an upward slope or a downward slope, when the sliding door is half-open, there has been a danger of the sliding door starting to move under its own weight and opening or closing at a considerable speed.